Thread-controlling mechanism for sewing-machines.



No. 804,508. PATENTED NOV. 14, 1905. J. H. (in J. B. URSBRUGK.

THREAD CONTROLLING MECHANISM FOR SEWING- MACHINES.

APPLIOATION FILED AUG. 12. 1004.

2 SHEETS-SHEET 1.

WI TNES5ES ATTORNEY.

No. 804,508. PATENTBD NOV. 14, 1905. J. H. in J'. B. URSBRUOK. THREADCONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED AUG. 18,1904.

2 SHEETS-SHEET Z.

IHVEN TORI jm/fmw/c ya 46W WITNESSES nrronm'.

parirnp sTA rEs PATENT OFFIUE.

JOHN H. URSBRUOK AND JOSEPH B. URSBRUOK, OF PHILADELPHIA, PENNSYLVANIA,ASSIGNORS OF ONE-HALF TO JOHN A. HUNTER AND MARY A. HUNTER, OFPHILADELPHIA, PENNSYLVANIA.

'l'IHHIEAD CONTIHOLLlNG IVIECHANISM'FOR SEWING-MACHINES.

Specification of Letters Patent.

Patented Nov. 14, 1905.

Application filed August 18, 190 1. $eria1 No. 221,182.

To all whom it may concern.-

Be it known that we, JOHN H. URSBRUOK and J OSEPH B. URSBRUOK, citizensof the United States, residing in the city of Philadelphia,

State of Pennsylvania, have jointly invented certain new and usefulImprovements in Thread-Controlling Mechanism for Sewing Machines, ofwhich the following is a full, clear, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

Our invention relates to sewing-machines wherein it is essential ordesirable to so operate the tension device for the lower thread that theexact length of thread drawn forward necessary to form a stitch may bepositively regulated and controlled and the tightening of such stitch beeffected by a positive braking of the tension-drum at suitable intervalsand during the formation of such stitch and after the length of threadnecessary to make the same has been let off the tension-drum by thecorresponding alternate release of the brake mechanism.

In sewing-machines designed for boot and shoe sewing, wherein a waxedthread is employed, it is desirable, if not essential, to produce aperfect product that no more thread than is necessary to form the stitchshould be let off and that the stitch should be drawn tight.

Our invention is especially advantageous to produce both those results,as our brake device operates to positively restrain rotation of thetensioned thread-drum at each stitchforming interval, hence operating todraw tight the previously-formed stitch.

Our present invention consists in supplying such a positive let-off andbrake device in mechanical and functional coaction with a thread-drumcontrolled, primarily, by a tension device, the brake device and thetension device controlling the rotation of the drum alternately, theinterval of time between the alternate action of each being governed bycam mechanism of the sewing-machine acting in unison of time with thestitch-forming devices thereof.

table thread-drum mounted thereon, and the tension device for the same.Fig. 3 is an end view of the device shown in Fig. 1, and Fig. 4c is alike view from the opposite end of the same device.

We need not describe in detail a lock-stitch boot or shoe sewing machinenor its positivelyacting cam devices to actuate the hereinafterdescribedbrake-controlled tension-drum, it being suflicient to refer to LettersPatent No. 715,323 granted to us, dated December 9, 1902, wherein such asewing-machine with which our present invention is adapted to operate istherein fully set forth.

Referring now to the accompanying drawings, 1 indicates a suitableframework constituting part of the frame of the sewing-machine and inproximity to the main cam-wheel of the machine, such as the cam-wheel 3,carrying cams A and 5. (Shown in Fig. 2 of the drawings of our saidPatentNo. 715,323.) A supporting plate 2 is screwed fast to saidframework 1, and upon said plate is a stud 2 upon which is rotatablymounted the tensiondrum 65, which is therefore free to rotate on saidstud under the yieldingly restraining influence of the tensionmechanism, save when positively held from rotation by the action of thebrake mechanism. The tension-drum is provided with an annular groove 65*for the passage of the thread and a bearing-surface on which thefriction -shoes 68 of the brake-levers 66 and 67 impinge. (See Figs. 3and 4.) On the end of the stud 2* which projects beyond the face of thedrum 65 and bearing against the same is a collar 6, serving as a bearingfor a spiral spring 7, and on the end of the stud and bearing againstthe spring is a thumbnut 8, said elements 6, 7, and 8 constituting thetension device, the mode of operation of which in creating the desiredtension is obvious. The needle-thread is drawn from a spool suitablylocated on the frame of the sewing-machine and passes around the drum 65in the groove 65 thereof, being led and directed thereto by theguide-wheel 9 (see Fig. 4) and being held on the latter by a coverhook10. The relative position of the guidewheel to the thread-drum is bestseen in the side elevation in Fig. 1. This guide-wheel is mountedrotatably on the lower end of the arm 71, which carries on its other enda friction-roller 72, which is disposed in the path of actuating-cams,such as cams L and 5 on the periphery of a cam-wheel, such as camwheel3, (shown and described in our aforesaid Patent No. 715,823,) or othersuitable actuating devices. The adjustment of position of theguide-wheel 9 relatively to the threaddrum is effected as follows: Thesaid guidewheel is rotatably mounted by means of the centrally-disposedset-screw on the lower end of the arm 71, which is centrally slotted andslides longitudinally between the spaced parts of the bracket 74, aset-screw passing through the slot in the arm 71, holding the spacedparts of the bracket-arm 74 together. (See Fig. 1.) The lower portion ofthe arm 71, whereon the guide-wheel 9 is mounted, projects below thebracket-arm 7a, and the slid ing movement referred to is effected, asseen in Fig. 4:, by means of the set-screw 75. In said Fig. 4c, which isan end View, the guidewheel 9 will be seen mounted by its shaft on thelower end of the adjustable arm 71 above the lower end of the bracket7a, in which said arm 71 is adjustable longitudinally by means of theset-screw 75, which has its bearing in said lower end of the bracket. Asis obvious from Fig. 4:, a forward turn of the set-screw in its bearing(which is fixed relatively to the arm 71) will effect a longitudinaladjustment of the arm 71 in its bracket-bearing 7 4:, thereby alteringthe position not only of the friction-roller 72, but of the thread-guidewheel 9, relatively to the tension-drum 65 and relatively to the brakemechanism governing the drum.

The bracket-frame 74 (carrying the arm 71 with its friction-roller 72and guide-wheel 9) is mounted pivotally on the supporting-frame 2,preferably and as shown in the drawing Fig. 1, by means of a lever 70,mounted to rock on the stud 2 between the face of the frame 2 and theinner face of the thread-drum 65. That method and means of pivotallymounting the arm 71 enables us to employ the rocking lever for theadditional purpose of actuating the brake-levers 66 and 67 though we donot limit ourselves to that precise mechanism for performing thatfunction.

The brake mechanism consists of the lever 66 and the lever 67, or eitherof them singly. Each carries a friction-shoe 68. We prefer to use adouble brake, for the reason that when one such lever only is employedthe braking is effected by causing the drum 65 to bind on the stud 2while by using both the rotation of the drum is prevented by a bitingaction between the two oppositely-disposed brake-levers and withoutpressing the drum against its supporting-stud. Each of thesebrake-levers 66 and 67 is hung by a pivot-pin 66 and 67 to thesupporting-frame 2 at diagonally opposite corners. Each brake-lever 66and 67 is connected to the rocking lever 70 by a link connection 69. Inthis preferred form of our invention the link connection joining thefree ends of either or both of the brake-levers 66 and 67 to the rockinglever 7 0 being on the fulcrum side of the latter and the brake-leversbeing also likewise suitably disposed, a rocking movement of the lever70 through the actuating-arm 71 will tend to draw the friction-shoes ofthe brake-levers against the periphery of the thread-drum 65 andpositively arrest its revolubility, while movement of said parts in theopposite direction will release the brake and allow the drum to rotateunder the yielding restraint of the tension-spring only. In order toinsure a quick and positive release motion of the brak elever, we preferto add a spring 10, (see Fig. 1,) one end of which is fixed at thefixedlypivoted end of the brake-lever and the other end is passed undera projection 11 on the free or linked end thereof.

W'e desire it understood that we do not confine ourselves to thespecific mechanism shown and described, as many of the adjunctiveelements may be varied or even omitted. We have shown separately in Fig.2 (read in connection with Figs. 3 and 4) the features which areabsolutely essential to any embodiment of our invention, these being thesupportingframe 2, the stud 2 the thread-drum axially and rotatablymounted thereon, the tension device yieldingly governing the rotation ofthe drum under the pull of the thread, and the brake-lever 66, carryingfriction-shoe 68 and pivotally mounted at one end on thesupporting-frame which carries the thread-drum in such manner that itmay be vibrated in both directions by appropriate means actuating itsfree end and its friction-shoe be thereby brought into and out ofcontact with the periphery of the thread-drum normally controlled by thetension device.

Having thus described our invention, what we claim as new, and desire tosecure by Letters Patent, is

1. The combination in a sewing-machine of a peripherally-grooved threaddrum about which the thread is passed, a supporting-frame carrying astud on which said drum is axially and rotatably mounted, tensiondevices mounted on said stud operating to limit the free rotation of thedrum, a braking mechanism adapted to positively restrain its rotation ateach stitch-forming interval, consisting of a brake-lever carrying abrake-shoe and pivotally mounted by one of its ends on saidsupporting-frame and over the periphery of the drum, and means tovibrate the brake-lever in both directions, consisting of a rockinglever pivoted axially of the drum with connecting actuating meansbetween it and the brakelever.

2. The combination, in a sewing-machine, of a thread-drum about whichthe thread is passed, a supporting-frame upon which said drum is axiallyand rotatably mounted, tension mechanism normally acting on the drum,

a rocking lever pivoted axially of the drum, a brake-lever carrying afriction-shoe and pivotally mounted by one of its ends on saidsupporting-frame, over the periphery of the drum, and a link connectingthe free end of the brake-lever with one end of the rocking lever.

3. The combination, in a sewing-machine, of a su pporting-frame carryinga stud, a tension-controlled thread-drum axially and rotatably mountedon said stud, a brake-lever carrying a friction-shoe and pivotallymounted by one end on the supporting-frame and over the periphery of thedrum, means to vibrate the free end of the brake-lever at predeterminedtimes, a guide-wheel about Which the thread is passed on its passage tothe threaddrum, and means to adjustably support said guide-Wheel infront of the threaddrum and to automatically raise and lower it as thebrake-lever is vibrated to brake or release the thread-drum.

{1. The combination in a sewing-machine,

of a supportingframe carrying a stud, a rocking lever axially mounted onsaid stud, a thread-drum rotatably mounted thereon, a tension device onthe end of the stud normally governing the free rotation of the drum, abrake-lever carrying afriction-shoe, and pivotally mounted byone end tosaid supportingframe, link connection between the free end of thebrake-lever and one end of the rocking lever, a bracket fixedly securedto one end of the rocking lever, an arm adjustably mounted in saidbracket and carrying at one end a friction-roller and at the other end aguidewheel arranged in the path of the thread as it is let off to thethread-drum.

In testimony whereof We have hereunto affixed our signatures this 16thday of April, A. D. 1904.

JOHN H. URSBRUCK. JOSEPH B. URSBRUCK. -Witnesses:

A. FLoRnNon Ynnenn, A. M. BIDDLE.

